Sexual violence, which includes both sexual coercion and assault, is a significant problem on college campuses due to its high prevalence and adverse consequences. Many campuses offer sexual violence prevention programs, but few have been rigorously evaluated. Of the few that have demonstrated positive effects in reducing rates of violence, most are costly to disseminate broadly (e.g., they require highly trained facilitators and/or are offered only to small groups of students at a time). In short, there is a need to develop methods for preventing sexual violence on college campuses that are cost-effective for delivery to large groups of students. The proposed research will evaluate an innovative video bystander program, which has the potential to be implemented broadly and cost-effectively across college campuses. In addition, the proposed research will attempt to evaluate an innovative methodology for assessing bystander behavior that makes use of virtual reality technology. We believe this new method has the potential to offer stronger and more definitive evidence of program effects than self-report methods alone, which are the current state-of-the-art method for assessing bystander behavior. We will recruit 1,000 first-year college students-250 students will be recruited from each of 4 college campuses (Southern Methodist University, Marquette University, William Paterson University, and Stony Brook University). After a baseline assessment, students will be randomly assigned to view one of two video programs: TakeCARE (the video bystander program) or a control video program. A post-treatment assessment will be completed within a week of viewing the video program, and follow-up assessments will be completed 2 months and 6 months after baseline. The proposed research is also designed to identify possible mediators (e.g., increasing confidence that one can do something) and moderators (e.g., sex, campus climate) of program effects, program effects on participants' own violence (perpetration and victimization) and possible adverse consequences of bystander behavior. The problem of sexual violence on college campuses is complex, but depending on the findings, this research could have an enormous impact on efforts to address this problem.